Glasgow giants Celtic have been told they need the return of Rangers to the top flight if their global value is to continue rising.

The Parkhead club have impressively defied a major downturn in the Scottish game to retain their place among the top 50 brands in world football.

The Premiership champions were ranked 34th in the list compiled by one of the world's leading valuation and strategy consultants.

London-based firm Brand Finance take a range of economic and football factors into account before awarding clubs credit ratings from AAA+ to D.

Despite failing to make the Champions League, Celtic still managed to rise four places on the index which saw Manchester United become the first billion dollar football brand.

However, with English Premier League sides growing at a rate of knots on the back of the recent £5.2 billion television deal signed with Sky and BT Sport then Brand Finance feel the Hoops will struggle to keep mixing it with the game’s elite.

BF communications director Robert Haigh said: “In terms of Celtic it is quite disappointing that Rangers were not promoted because for their brand to continue growing then it really needs the Old Firm fixture.

“It is quite impressive they are still in the top 50 because outwith the major leagues – the Premier League, Serie A, La Liga and the Bundesliga – there are only two clubs above Celtic in the table and they are Ajax and Galatasaray.

“Scotland is even smaller than both of those countries in terms of population so it is a major achievement.

“But if Rangers were to get back into the top tier that would be a further boost for Celtic in terms of cementing their position.

“Celtic are firmly ensconced in the top 50 with a brand value of £72million and it would take a significant decline for them to drop out.

“For a club of their stature Celtic have a relatively strong brand for a club, however, the rate of growth south of the border could see them start to lag behind in future years without a resurgent Rangers.”

It is a sign of the times that the likes of Stoke City, Crystal Palace, Sunderland and Swansea are starting to leave Scottish clubs trailing in their wake when it comes to generating cash, the Daily Record reports.

Haigh said: “The Premier League television deal is the main factor why these so called smaller clubs are flourishing. The TV income makes up a huge proportion of their revenues.

“The Premier League brand is almost an endorsement for being a major club these days even if you are not in the Champions League. If Celtic were to join the Premier League they would more than double their brand value overnight.

“That would take them closer to the big league but still some way behind Manchester United.

“Despite not winning a trophy for two years they signed a record breaking sponsorship deal with Chevrolet and a kit supply deal with Adidas worth £750m.” Rangers remain a long way detached from the super powers of European football following three years of wretched financial mismanagement but there could still be a place for them at the top table if they get their house in order.